FIG. 1 is a front elevational view of an arithmetic and control unit showing my new design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front, top, left perspective view thereof;

FIG. 8 is a front, bottom, right perspective view thereof;

FIG. 9 is a rear, top, left perspective view thereof;

FIG. 10 is a front elevational view thereof in the open position;

FIG. 11 is a rear elevational view thereof;

FIG. 12 is a left side elevational view thereof;

FIG. 13 is a right side elevational view thereof;

FIG. 14 is a top plan view thereof;

FIG. 15 is a bottom plan view thereof;

FIG. 16 is a front, top, left perspective view thereof;

FIG. 17 is a front, bottom, right perspective view thereof; and,

FIG. 18 is a rear, top, left perspective view thereof.

The broken lines shown in the drawings are for the purpose of illustrating unclaimed portions of the arithmetic and control unit and form no part of the claimed design.